1. Field of the Invention
The present invention concerns joints utilized in structures. Even more particularly, the present invention concerns the application of a premanufactured joint seal system (a joint seal system with a finished, dry surface) allowing expansion and contractions of different construction members.
2. Description of the Prior Art
In the construction of buildings and roads having multiple panels therein, there has long existed the need for joints and other similar means to connect substrates and accommodate the expansion and construction of these substrates due to thermal conditions. Such joints used in highways have been termed horizontal joints. Those utilized in buildings notably in skyscrapers, have been termed vertical joints. Those joints within buildings which interconnect with vertical joints or other vertical members are termed vertical-horizontal joints.
In selecting among the known materials to form a vertical joint, architects and specifiers have suggested the use of elastomeric sealant such as silicone sealant or organic based sealant. These types of sealants are normally applied wet into a joint opening. Before solidifying, some sealant types would readily sag and slump within the joint especially wider joints and/or collect dirt due to its wet surface in the uncured stage and/or are permanently deformed due to movement of the construction members while the sealant has not totally cured. This produced an uneven joint, which could not perform in the needed manner nor insure a watertight seal.
An example of one method of attempting a silicone seal over a wide vertical joint is described in U.S. Pat. No. 5,335,466 to Langohr. Langohr utilizes an open foam backer to maintain the position of an in place cured sealant strip; the backer and cured sealant strip cooperate to form a pair of grooves which are then filled with an uncured silicone sealant. This system requires a time consuming and labor intensive manufacturing process of depositing and curing a strip of silicone on the foam backing and then an installation process of dual beads of silicone sealant after the foam backing is installed (exposing uncured sealant during application). The resulting seal relies upon four bonds formed by the two beads (each bead forms one bond with the structure and one bond with the cured sealant). Contact between the cured sealant and the structure is only effected by the application of the bead sealant (Col 3, Line 67-Col 4, Line 1). The Langohr system is very wasteful of silicone sealant. The depth of the cured sealant strip (and thus two sealant beads) is substantial to permit sufficient uncured sealant to be added to assure the beads are sufficiently uniform to effect a watertight seal even with flow between application and cure and a smoothing operation for appearance. Further, the three bead appearance is not preferred, particularly where the center bead width differs from the width of the beads of uncured sealant applied. Further still, the foam backer remains adhered to the cured sealant and the bead sealant to provide structural stability to the joint. Another disadvantage is the appearance of the joint if there has been shifting and the space is uneven; the cured sealant will be uniform but the bead sealant will be uneven. Further, wet sealant can collect dirt or debris while curing, creating an unsightly appearance.
The present invention provides a decorative and easily formed sealing strip for wide vertical joints, which covers the joint with a performed uniform strip or forms a U-shaped seal by inserting the sealing strip deeper into the joint. The present invention also provides a xe2x80x9cdryxe2x80x9d outer seal for all types of joints, wide or narrow, vertical or horizontal, which will not deform due to shifting and which will not collect surface debris as the adhesive dries.
The seal of the present invention comprises:
a) a resilient backing member for compression insertion into a joint
b) an elastomeric sealing strip disposed on the backing member and wider than the joint, and
c) an adhesive joining a central elongated portion of the sealing strip to the backing member.
The backing member holds the sealing strip in place during installation and centers the strip relative to the joint, holding the strip in place while an added adhesive sets. There are various configurations for the backing member to reduce cost, to facilitate insertions, and if needed to minimize adhesion between the backing member and the sealing strip. It is preferred that the sealing strip is adhered to the backing member in a way so that the reaction to expansion or contraction in the joint does not effect the sealant strip. The sealing strip is adhered directly to the structure below the edge on either side with an added adhesive. Thus, adhesive is never exposed to the open. The resultant seal is watertight and yet flexible enough to endure the expansion and contraction of the joint.
Other objects, features and advantages of the present invention will become apparent from the subsequent description and appended claims, taken in conjunction with the accompanying drawings.